BBB - L6 - Taste

What is another term for the sense of taste?

gustation - allows perception of taste through chemical stimuli

What is the name of the muscular organ which is the primary organ of gustation?

the tongue

What is the surface of the tongue covered in?

papillae and taste buds (different papillae across tongue) - tiny bumps ON papillae are our taste buds

What is the sense organ for taste?

taste buds

where are taste receptors located?

on and under tongue, on soft palate, side and back of mouth

How many receptor types are grouped into a taste bud?

5

What are the the 5 receptor types grouped into taste buds?

sweet, sour, salty, bitter, umami

How do the receptors work in our taste buds?

they respond to different chemical components → chemicals from food must first dissolve in saliva

About how many clusters of taste receptor cells consists of in each taste bud?

50 - 150

Why does our ‘taste’ change over time?

it appears to change because by the age of 20, we lose half our receptors

stimuli interact with receptors tips, opening ion channels, leading to change in ______ potential

membrane

what types of papillae are there?

circumvallate, foliate, fungiform

form/location of circumvallate papillae?

large, round - back of tongue

form/location of foliate papillae?

arranged in folds - sides of tongue

form/location of fungiform papillae?

mushroom-shaped - scattered but primarily tip of tongue

How does the sense of taste travel from taste buds to the brain?

nerve fibres connected to taste buds travel from tastebuds to the brain stem via cranial nerves - forms the gustatory nerve

How many pathways does the gustatory nerve divide into?

2

What is the first pathway that the gustatory nerve take?

through posterior medulla to ventroposterior medial nucleus of thalamus - from there two SUB-pathways

What are the sub-pathways that are taken from pathway one of the gustatory nerve?

-one to primary somatosensory cortex (for tactile info)
-one to gustatory cortex of the insula (for flavour)

What is the second pathway the gustatory nerve divides into?

projects through pons to hypothalamus and amygdala → hypothesized to play a role in feeding behaviour

what are 3 abnormalities of taste?

ageusia, hypogeusia, dysgeusia

what is the definition of ageusia?

absence of the sense of taste

What may ageusia be caused by?

may be caused due to cranial nerve damage or problems with endocrine system (eg, salivary glands)

what is the definition of hypogeusia?

diminished taste sensitivity

what may cause hypogeusia?

often due to medication

what is the definition of dysgeusia?

disturbed sense of taste - various potential causes/treatments, diagnosis complicated as taste is tied with other sensory systems

what may cause dysgeusia?

various potential causes/treatments, diagnosis complicated as taste is tied with other sensory systems